According to statistics, in recent years the number of depressed patients has increased significantly. This phenomenon is associated with profound changes in modern life (acceleration, mechanization, migration of large groups of people, etc.) K. Kirov notes that experienced clinicians based on comparative studies over the past 10 years have come to the conclusion that melancholic syndromes have become not only meet more often, but significant changes have occurred in their structure. Thus, melancholic delirium with cyclophrenia loses its religious-irrational character and is replaced by the ideas of self-accusation. The classical picture of the clinic of melancholy has changed, a lot of atypical, hidden (disguised) outpatient forms have appeared. In-depth clinical observations have enriched the classification of depressive states with new forms and concepts, familiarization with which is important not only from a diagnostic point of view, but also for the correct therapeutic approach. The treatment plan for depressive diseases is based on the same principles as for schizophrenia, taking into account the characteristics of the leading (targeted) syndrome and nosological affiliation of the disease. The clinical characteristics of the leading psychotic syndrome orient the therapist in the correct choice of the most effective drug. The primary task facing the doctor is to make the correct etiological diagnosis, that is, to determine whether the depression is endogenous, organic or reactive. The etiological diagnosis determines the choice of the main type of treatment – pharmacotherapy, psychotherapy, general somatic therapy, etc. We believe that the classification of depressive conditions Kielholz, based mainly on the provisions of Selbach and Hippius, is very useful for the theoretical justification of the pharmacotherapy of depression. Organic Depression. As you know, Schneider and Weitbrecht believe that the basis of all exogenous, organic and symptomatic depressions is the physical condition of the body. However, when considering the problems of treating these diseases according to Kielholz, the group of organic depressions should include those that are determined by structural changes in the brain, and symptomatic depressions – psychotic patterns that arise as a syndrome associated with extracerebral diseases. Organic depressions include depressive syndromes in senile dementia, atherosclerosis, progressive paralysis, epilepsy, oligophrenia, and others. From a clinical point of view, in addition to differences in the strength and nature of the picture of depression, there is an organic psychosyndrome according to Bleuler: memory impairment, orientation disorder, impaired thinking tendency to confabulation, affective symptoms, etc. Delirium is most often nihilistic in nature. Symptomatic depression. As already mentioned, they are syndromes associated with certain extracerebral diseases or effects. These include depressive states in various diseases of an infectious, hemodynamic, endocrine, toxic nature, etc.